I know this thread is a few months old by now, but I fully support this idea.
Especially since there's no way now to change the ID of a Legacy name, it makes no sens that LN/older IDs should be 'spotlight locked'
A lot of older users with LN/old IDs are leaving the site (or have left already) and adopt out their pets. It's sad that a lot of those old LN/IDs can't win the spotlight again after changing owners. Soren does make a good point too about revamped pets. I'm 31, I've been on this site since I'm 13. Some of my pets I've had since 2012. It makes no sense for users like me to not be able to revamp an old pet and have it win spotlight again.
That all being said, with how little users have an interest in pets these days, I don't really see pets winning with the exact same profile and story being much of an issue. There's what? Maybe a hundred users that care about spotlight now? Will it really make a difference in the end? We don't even get the spotlight once a WEEK at the moment anyways...
While I probably wouldn't ever want to revamp my spotlight-winning pets (I think my first spotlight win was December 2011.... and that's making me feel old now!!), I think it would help keep some interest in the spotlight if pets who have won previously, can be entered again with a brand new look / theme (please not just exactly the same again - you've already won once with that!), maybe after a set length of time.
I've seen so many pets UFA that have won the spotlight that I feel I have to skip past, as I want to be able to have all of my pets spotlight-worthy (eventually). And I'm sure I'm not the only one who skips those 'UFA past winners' as they then can't be entered again.
Given that we're down to one winner a week (once it's back up and running properly), this really could help to add some more profiles to the queue and hopefully get the spotlight back to it's previous number of days in the week!
(edited to add) ** I really really don't want to see spotlight winners being able to win again with exactly the same profile / story etc, especially while the spotlight is only once a week - if the spotlight was 5 days a week, then that wouldn't be too bad, but certainly while it's once a week, I think we need to stick to those pets with 'new' content (could be previous winners with a new profile / story / whatever)

Doubling down on support for this, because I've seen myself and others recently have to pass up UFA LNs because they had already won the spotlight. Such a bummer to feel like you have to choose between those two things! I would at the very least like to see the option exist when you adopt a pet / have a pet transferred to you.
I love this and completely agree! I've won the Spotlight over 114 times now, and I'm very proud of that. My goal was 100 and when I reached that I was ecstatic. It only took me 12 years... lol I dearly love my little pixels, and I have worked very hard on all of them. But I do get bored and want to be inspired to create new profiles by having new pets. So some of the ones that have already won (that I can part with) I will adopt out. However, after all the training and reading and work like that I've put into my pets, I wish I could have the option to revamp them and possibly win again. At least have the option. :)